package com.seatiger.structure.stack;

import com.seatiger.structure.array.Array;

/**
 * 使用动态数组实现栈
 * @param <E>
 */
public class ArrayStack<E> implements Stack<E> {
    private Array<E> array;

    public ArrayStack (int capacity){
        this.array = new Array<>(capacity);
    }
    public ArrayStack(){
        this.array = new Array<>();
    }

    /**
     * 获取容量大小
     * @return
     */
    public int getCapacity(){
        return array.getCapacity();
    }

    @Override
    public void push(E e) {
        array.addLast(e);
    }

    @Override
    public E pop() {
        return array.removeLast();
    }

    @Override
    public E peek() {
        return array.getLast();
    }

    @Override
    public int getSize() {
        return array.getSize();
    }

    @Override
    public boolean isEmpty() {
        return array.isEmpty();
    }

    @Override
    public String toString() {
        StringBuilder res = new StringBuilder();
        res.append("Stack: ");
        res.append("[");
        for (int i = 0; i < array.getSize();i++) {
            res.append(array.get(i));
            if (i != array.getSize() - 1) {
                res.append(",");
            }
        }
        res.append("] top");
        return res.toString();
    }
}
